1. Field of the Invention
This invention relates to a chisel holder for a road milling machine or the like, having a base element which supports a holding neck, wherein the holding neck has a chisel receiver and a protrusion is connected to the base element upstream of the holding neck when viewed in an advancing direction of the tool.
2. Discussion of Related Art
A chisel holder is known from German Patent Reference DE 43 22 401 C2 (U.S. Pat. No. 5,683,144). The known chisel holder has a plug-in neck, by which it is exchangeably held in a plug-in receiver of a base body. The base body is fastened on an outer circumference of a milling roller tube. The plug-in neck of the chisel holder is connected in one piece to a base element. On a side facing away from the plug-in neck, the base element has a holding neck. The holding neck has a bore into which a shank chisel can be inserted in a known manner. By way of example, German Patent Reference DE 37 01 905 C1 (U.S. Pat. No. 4,818,027) shows a possible assembly situation.
The holding neck of the chisel holder has a cylindrical section, into which wear markers designed as encircling groove-like depressions are cut. In the area upstream of the holding neck, when viewed in the advancing direction of the tool, the base element has a protrusion designed in a form of an apron, which covers a surface of the base body into which the plug-in receiver for the plug-in neck is cut. This area of the base body is thus protected. Chisel holders are also known in the prior art which are directly fastened on the milling roller tube without a base body.
The above described chisel holders are employed in road milling machines, but also in species-related earth processing machinery, such as soil stabilizers, mining machinery, etc. The power consumption of the machine changes as a function of the nature of the ground to be worked. It is known that coverings built up in layers which, when cut, tend to form clod-like chips, and offer a high resistance to the tool. Such chip shapes are generated, for example, when cutting asphalt surfaces in which an insufficient holding bond exists between the cover layer, mostly approximately 4 cm thick, and the binder layer.